In the field of waste incineration, slag removers serve to discharge from the incineration plant, in the course of the incineration, the residues (slag) which cannot be further incinerated.
Slag removers generally comprise a drop shaft, via which the combustion residues fall from the combustion chamber into a water-filled trough. From this, the combustion residues are pushed by means of a push ram over an expulsion chute or expulsion path, whence they can be transported onward in dumpable form.
One example of a slag remover is described, for instance, in DE-A-2539615. Here a discharge piston, which pushes into the expulsion chute the slag which falls onto the trough bottom, is articulately connected at its rear end to one or more thrust cranks, which are seated in a rotationally secure manner on a shaft which is rotatably mounted in bearings in the side walls of the trough. Disposed in a rotationally secure manner on both ends of the shaft, which ends project beyond the side walls, are lever arms, which respectively cooperate with a hydraulic piston-cylinder unit.
A drawback with such a slag remover is that, for instance, when slag is present which is conveyable only with great effort and this is distributed inhomogeneously over the trough cross section, load torques, which necessitate appropriate dimensioning of the shaft, are generated. Moreover, the moments of force which act on the respective bearing are in this slag remover relatively large, which is not conducive to optimal force transmission.
Since the lever arms must in most cases be removable, in a slag remover such as that according to DE-A-2539615, in which the force flow goes via the bearings disposed in the side walls, keyways are generally provided. However, as a result of the accompanying weakening of the shaft or lever arm, the mechanical stability thereof is impaired. Moreover, the fitting of keyways or corresponding keys is relatively complex and expensive.
A further slag remover is disclosed, for instance, in EP-A-0363645, according to which two push rods, which are mounted rotatably on a lever by means of a joint, are present. The lever is here configured as a two-armed lever, between whose arms a pivot shaft is disposed. As opposed to DE-A-2539615, according to EP-A-0363645 joints are prevented from dipping into the water fill of the trough. The problems with respect to the generation of load torques in the shaft persist, however.